• 한국통신학회논문지
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• 제29권8C호
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• pp.1142-1148
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• 2004

일반적으로 2채널의 헤드폰에서 입체음향을 생성하기 위해서는 HRTF(Head Related Transfer Function) DB를 이용한 바이노럴(binaural) 합성기법을 사용하게 된다(1). 그러나 비 개인화 된 HRTF DB를 이용하여 생성된 2채널 입체음향은 사용자에 따라 앞/ 뒤 또는 상/하 방향에 대해서 혼돈을 가져와 입체감을 저하시킬 수 있다. 본 논문에서는 앞/뒤 음상정위의 혼돈을 개선하기 위해 스펙트럼 단서를 부각시키는 기존의 알고리즘을 분석하고 이를 토대로 혼돈 방향의 HRTF의 차이 성분을 이용하여 스펙트럼 특성을 강조하는 방법을 제안하였다. 또한, 제안한 방식이 기존의 방법에 비해 앞/뒤 방향감이 개선됨을 청감평가 실험을 통해 확인하였다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2010년도 추계학술대회
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• pp.260-261
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• 2010

본 논문에서는 제작된 콘텐츠에 배경음을 간편하고 효과적으로 혼합하기 위해서 녹음된 신호(전경음)를 분석하여 배경음 에너지를 적응적으로 조절하는 배경음혼합 알고리즘을 제안한다. 이를 위해, 제안된 알고리즘은 등청감 곡선 (equal-loudness curve) 및 linear prediction (LP) 분석에 기반하여 전경음신호의 청감 에너지 및 음성신호 존재여부를 결정한다. 이에 따라 전경음에 음성신호가 존재하는 경우에는 음성이 명확하게 들릴 수 있도록 혼합된 배경음의 에너지를 하향 조절하고, 반대로 전경음에 음성신호가 존재하지 않는 경우에는 배경음이 명확하게 들릴 수 있도록 혼합된 배경음의 에너지를 상향 조절한다. 제안된 알고리즘의 효율성을 검증하기 위해, 고정 가중치를 이용하여 배경음을 혼합하는 경우와의 음질 선호도 조사를 실시한 결과, 제안된 알고리즘에 대한 높은 선호도를 보였다.

• 한국소음진동공학회논문집
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• 제20권8호
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• pp.742-752
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• 2010

In case of the working machine that using in the loud-noisy workplace, as it generates the loud-noise, it is influencing a physical, mental bad effect to those workers. Accordingly, though the noise countermeasure for the loud-noisy workplace is acutely requiring, until now, those methods that wearing the soundproof-protection tool, or restriction the working hours, and minimize the noise exposure volume, were mainly used. However, such noise countermeasures occur many problem points. On such point of view, using the acoustic simulation technique, let the workers to choose the workplace where suffering many damages due to the noise of working machine, and after grasp the physical property of working machine and indoor acoustic characteristic, this Study has attempted to grasp the reduction degree of noise level at before-improvement?after-improvement, through the sound-absorption measure. Passing through such preceding step, using auralizational technique based on the noise of working machine of before-improvement after-improvement, and by conduct psycho-acoustics evaluation, this study intended to investigate the change degree of subject reaction. As the result of evaluation, it is considering that the noise-reduction countermeasure method for the loud-noisy workplace could be much effective, through the sound-absorption measure.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.87-91
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• 2005

The effects of the movable reflectors on the stage acoustics in Seoul's Sejong Performing Arts Center (3,048-seat multi-purpose hall, stage area of $270m^2$ within an orchestra shell) and Ceramic Palace Hall (440-seat concert hall, stage area of $105m^2$) were investigated. Acoustical parameters were evaluated by measuring stage and audience acoustics in the two halls. The study was primarily based on the stage support parameter STI proposed by Gade (Acustica 65, pp.193-203, 1989). Results showed that STI varied on the stage of the large hall according to the position of the reflectors, whereas STI did not vary in the small hall. In the large hall, a smaller clear stage area (bounded by the reflectors) yields an increase in both STI and other early energy measures. In the small hall, early energy decreases when its stage's surface diffusion was covered with specular reflectors.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1991년도 춘계학술대회논문집; 한국해사기술연구소, 대전; 1 Jun. 1991
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• pp.53-56
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• 1991

산업구조의 급속한 발전과 공업화는 사회구조의 변화 및 대도시로의 인구집 중, 고밀도화, 교통량의 증가를 초래하여 이로부터 기인한 도시지역의 환경 오염 문제는 쾌적한 인간생활을 위협하는 단계에까지 이르렀다. 그중에서 소 음에 관한 문제도 대기 및 수질의 오염과 동시에 도시생활 환경에 많은 영 향을 미치게 되었다. 도시 소음의 주 원인은 주로 도로교통소음이며 이는 기 하급수적으로 늘어가는 자동차의 양에 의해 더욱 심해지고 있다. 따라서 현 재 우리나라에서도 주거지역 및 준주거지역 등의 지역별 소음도 규제 및 신 설되는 공동주택 단지에서의 소음레벨규제등이 있긴 하나 이들은 상당히 소 극적이며 미온적일 뿐 아니라 실제 거주하는 주민들의 반응과는 상당한 차 이를 보이고 있으며 더욱이 주민의 소음에 대한 주관적 반응을 적절히 표현 할 수 있는 지표마저 명확하지 않은 실정이다. 이러한 관점에서 본 고찰에서 는 피험자들의 주관적 반응을 실험할 때 발생하는 변수요인들을 통제 할 수 있는 실험 실시행 청감실험을 실시하기에 앞서 대상지역의 도로교통소음을 여러가지 평가척도에 의해 평가한 후 그 현장에서 이 소음에 노출된 피험자 들의 반응을 파악하여 청취자들이 인지하는 소음레벨을 적절히 평가하는 지 표를 찾고자 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.488-492
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• 2007

Since Equipment-Noises occurring in machine room penetrate wall-body and travel to the adjacent room in the form of air-borne sound and structure-borne sound, it is appearing as the main factor that injures a peaceful residential environment, and due to this, such noise-damage is currently increasing rapidly. Consequently, despite the measures for sound-insulation and soundproof against the equipment-noise penetrated wall-body is urgently required, but as the subjective evaluation considered for psychological response about the equipment-noise was not practiced, many dissatisfactions are still raising even after some measure was taken. On such point of view, this Research, at the spot, has actually measured the equipment-noise that had permeated various wall-bodies, and examined its physical characteristics, thence based upon this, has conducted Psycho-Acoustics Experiment and investigated the interrelation between the physical evaluation value and psychological reaction value. It is considered that such study result could be utilized as the useful material at the time of establishment of the Grading Standard for the insulation performance against the Architectural Plumbing Noise, in the future.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.263-267
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• 2007

Even though Waterpower Generation as pollution-free has its own merit of contribution by supply of good quality electricity, due to the noise made at the time of its operation, a normal mutual communication among the workers and technicians engaging at the hydraulic turbine dynamo room is almost impossible, and since those finishing materials had been used mainly by reflection material, it is actual situation that when working for maintenance in the hydraulic turbine dynamo room, as counterpart's voice vibrates, its working efficiency is difficult to ensure. On such view point, this Research has conducted Psycho-acoustics Experiment about voice Definition using Auralizational Technique, on the object for the hydraulic turbine dynamo room that improved its acoustic performance by computer simulation. As the result of Study, it was known that the clearness of sound with regard to voice information transmission was apparently improved in all items than before improvement. Therefore, it is considering that these results would be utilized usefully when renovation on the hydraulic turbine dynamo room in the future.

• 한국소음진동공학회논문집
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• 제18권3호
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• pp.335-344
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• 2008

In recent years, public complaints against railroad noise by KTX and Ordinary train have been rising. Regulation of railways noise uses same standard without distinguishing the type of railroad cars. According to the type of railroad cars, the frequency characteristics of emitting noise is different. Therefore it is requested to know how the public response vary to each types of railroad cars. The noise annoyance from three types of trains(KTX, electric train, diesel train) was analyzed by jury evaluation test for assessing the effect of frequency characteristics. The numerical results by a semantic differential method showed that annoyance response to three type of trains depended on the frequency characteristics. As a result, this study proposed that the KTX could have a bonus level of maximum 2.9 dB(A) compared to ordinary train.

• 환경위생공학
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• 제17권2호
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• pp.55-62
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• 2002

For my thesis I have analyzed the differences between the traffic noise level surrounding the schools and the perceived level of noise. 1 have used the ways of measurement and questionnaires to support my study. According to the analysis, the measured noise level was higher than the expected noise level. The equivalent noise level was proven to be higher when the windows of the classrooms were open. The noise level was also higher on the third floor than the first floor. The correlation between the measured noise level and the perceived level of noise was tested in each school. The school which had a higher expected noise level showed a high perceived level of noise. The measured noise level and the perceived level of noise became larger on the higher floors. Through the questionnaires, the traffic noises were proven to be the largest noise-making source surrounding the schools. Most of the students replied on the questionnaires that they have been consistently bothered by the noise. It interfered with their studies and concentration. Also, the sound of their voices became louder because of the noise around their schools. Therefore, I have come to the conclusion that the traffic noises that surround the schools give the students negative influences.

• 한국음향학회:학술대회논문집
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• 한국음향학회 2004년도 추계학술발표대회논문집 제23권 2호
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• pp.291-294
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• 2004

본 논문에서는 잡음의 변화(variance)가 없는 정적인 통계적 특성(Stationary Static Characteristic)을 갖는 환경에서 잡음 추정을 통해 지각 필터의 성능을 개선하는 알고리즘을 제안한다. 제안된 잡음 추정 알고리즘은 입력되는 잡음에 열화 된 신호의 묵음 구간에서 추정된 잡음을 이용하여 입력되는 잡음의 SNR을 추정 후, 대역 별로 smoothing 상수 값으로 잡음 에너지를 제어하여 첨가된 잡음을 추정함으로써 초기 추정 잡음 보다 가까운 추정 잡음을 얻을 수 있게 된다. 이는 신호를 열화 시킨 잡음을 보다 정확한 추정을 제공함으로써, 지각 필터의 응답을 개선할 수 있고 더불어 잡음에 의해 열화 된 신호의 음질을 개선할 수 있다. 또한 저 대역에 영향을 미치는 잡음인 경우 다른 방법들과는 달리 음질의 개선이 뚜렷하다. 기존의 방식과 비교를 위해 다양한 신호 대 잡음 비(signal-to-noise ratio, SNR)에서 열화 된 오디오 신호를 입력으로 사용하였다. 입력 SNR이 5dB, 10dB, 15dB와 20dB의 각각의 경우에 대하여 SSNR(Segmental SNR)과 잡음 대 마스킹 비(Noise-to-mask ratio, NMR), 음질 테스트를 수행한 결과, 청감 테스트(Mean Opinion Score, MOS Test) 결과의 향상과 음질개선의 개선을 확인할 수 있었다.